Mental Fatigue on Reaction Time and Game Performance in Esport Players

Electronic sports (e-sports) gained popularity in the early 2000s within the computer gaming community and reached an audience of approximately 395 million people worldwide by 2018 (Bányai et al., 2019; Nagorsky and Wiemeyer, 2020). The exponential growth of e-sports globally has led to its recognition as a sport, creating employment opportunities for players who master and showcase game-related skills, turning e-sports players into professional athletes supported by well-known companies, and providing the chance to win large cash prizes (Seo, 2013; Giakoni-Ramírez et al., 2022). As a result of this progress, it is estimated that the number of global players could reach 3.38 million in 2023, with revenues reaching $184.0 billion (Report, 2023). E-sports refers to competitive video games where teams or individuals compete against each other, and it is recognized as a sport activity that helps players develop and train their mental skills and hand-eye coordination (Adamus, 2012). Although it requires less physical activity and contact compared to most sports, e-sports shares some common aspects with traditional athletic sports. For instance, in games divided into tournaments and matches, players either individually or as a team face off against opponents. Other commonalities include players often practicing for hours every day, working professionally, and being able to secure sponsorships from companies (Jacobs, 2015). There are various computer games with different mechanics and competition rules that players must master. To reach and maintain peak performance, players need to continually exercise and improve their skills and abilities (Nagorsky and Wiemeyer, 2020). E-sports players must adapt their hand-eye coordination, respond quickly to changing conditions, and continuously adjust their reaction speeds (Steenbergen et al., 2015; Stewart et al., 2020; Urbaniak et al., 2020). Key components of e-sports performance include hitting accuracy for moving targets that quickly appear on the screen (hit accuracy) and rapid response to stimuli (reduced reaction time). In the literature, it has been observed that reaction time and hit accuracy are commonly evaluated to measure an e-sports player's performance (Koposov et al., 2020; Sainz et al., 2020; Luu et al., 2021; Ersin et al., 2022). Nagorsky and colleagues have stated that reaction time is the most important performance indicator in all e-sports disciplines (Nagorsky and Wiemeyer, 2020). Since reduced reaction time is crucial for the quick execution of decisions, it can be a factor that makes a difference in e-sports (Brandmeyer et al., 2021). According to recent literature, the Aim Lab software is one program that can measure and improve e-sports player performance (Roldan and Prasetyo, 2021). Researchers plan to use reaction time, hit accuracy, and the Aim Lab training application to evaluate e-sports players' performance. Mental fatigue is a psychobiological state that arises from prolonged cognitive activities (Marcora et al., 2009). It has been shown in the literature that mental fatigue induced by a protocol (e.g., the commonly used Stroop Test) reduces performance parameters such as running and total distance in various team sports (Smith et al., 2015), impairs running, passing, and shooting performance specific to soccer (Smith et al., 2016), and similarly negatively affects physical performance in cricket (Veness et al., 2017) and Australian football players (Weerakkody et al., 2021). Additionally, it has been reported that mental fatigue induced by the Stroop test affects passing decisions in professional soccer players (Gantois et al., 2020) and decreases decision-making performance in sub-elite soccer players (Trecroci et al., 2020).

Furthermore, it has been shown that playing sports-based video games or using social media also causes mental fatigue, negatively affecting decision-making and visuomotor skills (Fortes et al., 2020; Fortes et al., 2022; Fortes et al., 2023). Although the literature generally indicates that playing video games or using social media leads to mental fatigue, there are also studies suggesting otherwise. Ciocca and colleagues found that a 30-minute video-based tactical task did not cause mental fatigue and did not negatively affect physical or technical performance (Ciocca et al., 2022). For all these reasons, it is important to apply a structured fatigue protocol to ensure that the individual is genuinely mentally fatigued. Therefore, in our study, the 30-minute Stroop test will be used to induce mental fatigue, focusing on this gap in the literature.